The present invention relates to a semiconductor device, and more particularly relates to a semiconductor device that includes a semiconductor module having a semiconductor element and supplies drive power to an electric motor.
In recent years, electric vehicles provided with an electric motor as its driving power source are becoming popular. Electric vehicles are provided with a semiconductor device such as a PEU (Power Electronic Unit) that converts direct-current power supplied from a battery into alternating-current power and controls the supply of the power to the electric motor, and also according to need, performs a control such that alternating-current power generated by a regenerative mechanism is converted into direct-current power and the power is accumulated in a battery such at a time of braking, for example.
The power electronic unit is provided with a power module that converts direct-current power supplied from the battery into alternating-current power, and also according to need, converts the alternating-current power generated by the regenerative mechanism into direct-current power. Because such power modules are often used in plural, while positioning a plurality of power modules relatively close to each other, an electric wire electrically connecting the plurality of power modules with each other, and an electric wire electrically connecting the plurality of power modules with other constituent members and external devices, are routed near the power modules. Furthermore, in the power modules, because a relatively high electric current is used, power semiconductor elements such as a Power MOSFET (Metal Oxide Semiconductor Field Effect Transistor) or an IGBT (Insulated Gate Bipolar Transistor) are often incorporated as a switching element. Because the operations of such power semiconductor elements are accompanied by the generation of a large amount of heat, heat sinks are mounted on power modules in order to secure a radiation route.
Japanese Patent Application Laid-open Publication No. 2008-259398 relates to a power conversion device, and discloses a configuration in which a semiconductor module is fixed to a base board, and a conduction bus bar that provides conduction between the semiconductor module and the exterior of the device is positioned above the semiconductor module while being included in an input-side terminal board. In this power conversion device, the semiconductor module has a configuration in which a semiconductor chip is molded by resin, and the base board functions as a heat sink.